Increased usable instrument life in telesurgical systems

ABSTRACT

A telesurgical system operates in a first operating mode and in a second operating mode. In the first operating mode, a moveable component is driven within a first range of an operating parameter. In the second operating mode, the moveable component is driven with a second range of the operating parameter, less than the first range. Usable instrument life is increased by decreasing mechanical degradation of the moveable component as a result of operating in the second range. A surgeon may select either operating mode.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a non-provisional of and claims priority to U.S.Provisional Patent Application No. 62/543,726, filed on Aug. 10, 2017,the entire contents which are hereby incorporated by reference.

TECHNICAL FIELD

Inventive aspects are associated with operating modes for teleoperatedsurgical systems and instruments.

BACKGROUND

Minimally invasive surgical techniques may reduce the amount of damageto tissue during diagnostic or surgical procedures, thereby reducingpatient recovery time, discomfort, and unhealthy side effects. A commonform of minimally invasive surgery is endoscopy, and a common form ofendoscopy is laparoscopy, which is minimally invasive inspection andsurgery inside the abdominal cavity. In standard laparoscopic surgery, apatient's abdomen is insufflated with gas, and cannula sleeves arepassed through small (approximately one-half inch or less) incisions toprovide entry ports for surgical instruments. Other forms of minimallyinvasive surgery include thoracoscopy, arthroscopy, and similar“keyhole” surgeries that used to carry out surgical procedures in theabdomen, thorax, throat, rectum, joints, etc.

Teleoperated surgical systems that use computer assistance are known.These surgical systems are used for both minimally invasive surgeries,and also for “open” surgeries in which an incision is made sufficientlylarge to allow a surgeon to access a surgical site. Examples ofminimally invasive and open surgeries include the surgeries listedabove, as well as surgeries such as neurosurgery, joint replacementsurgery, vascular surgery, and the like, using both rigid- andflexible-shaft teleoperated surgical instruments. An example of ateleoperated surgical system is the da Vinci Xi® Surgical System (ModelIS4000), commercialized by Intuitive Surgical, Inc., Sunnyvale, Calif.Other examples include the Sensei® and Mageiian™ Systems commercializedby Hansen Medical (Auris Surgical Robotics Inc.), the RIO™ Systemcommercialized by Mako Surgical (Stryker Corporation), and the Flex®System commercialized by Medrobotics Corporation.

Teleoperated surgical systems may use interchangeable surgicalinstruments that are driven by robotic manipulator technology. Some ofthese instruments are intended for only a single use, or for use duringonly a single surgical procedure. These instruments are treated asdisposable because they are not used again. Some of these single-useinstruments are expensive, and consequently the cost of a surgicalprocedure increases. Other instrument types are designed for multipleuses, and these multiple-use instruments are typically cleaned andsterilized between surgical procedures. An advantage of multiple-useinstruments is that the instrument cost per surgical procedure isreduced. But, mechanical limitations such as cable wear limit the numberof times these multiple-use instruments can be used. Thus an increase inthe number of times a multiple-use instrument can be used will furtherreduce instrument cost per surgical procedure.

SUMMARY

In one aspect, a surgical system includes a teleoperated manipulator anda control system. An instrument is coupled to the manipulator, and theinstrument includes a movable mechanical component. The control systemoperates the surgical system in a first operating mode in which thecontrol system drives the movable mechanical component within a firstrange of an operating parameter, such as a full range of motion of themechanical component. And, the control system also operates the surgicalsystem in a second operating mode in which the control system drives themovable mechanical component with a second range of the operatingparameter that is more limited than the first range, such as less thanthe full range of motion of the mechanical component. Other operatingparameters include velocity, acceleration, and mechanical load. Andadditional operating modes and parameter ranges may optionally be used.

A surgeon may select one or more operating modes as clinically required.

The usable life of the instrument is reduced based on the extent ofoperating in the first operating mode and in the second operating mode.Alternately, the usable life of the instrument is reduced based on theextent of operating in the first operating parameter range and in thesecond operating parameter range. Operating within the second, morelimited parameter range results in relatively less mechanical wear onthe component. The amount of usable life remaining on the instrument isreduced by one amount corresponding to operating in the first operatingmode or within the first parameter range, and the amount of usable liferemaining on the instrument is reduced by a second amount, less than thefirst amount, corresponding to operating in the first operating mode orwithin the first parameter range. As a result, an instrument's usablelife is increased, and overall cost per surgical procedure is reduced.

Additional aspects of limiting mechanical component operation togenerate a corresponding increase in usable instrument life arepresented.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a telesurgical system.

FIG. 2 is a schematic view of an instrument of the telesurgical systemand example operating parameter ranges.

FIGS. 3A-3C are schematic views of instrument components and exampleassociated operating parameter ranges.

DETAILED DESCRIPTION

This description and the accompanying drawings that illustrate inventiveaspects, embodiments, implementations, or applications should not betaken as limiting—the claims define the protected invention. Variousmechanical, compositional, structural, electrical, and operationalchanges may be made without departing from the spirit and scope of thisdescription and the claims. In some instances, well-known circuits,structures, or techniques have not been shown or described in detail inorder not to obscure the invention. Like numbers in two or more figuresrepresent the same or similar elements.

Further, specific words chosen to describe one or more embodiments andoptional elements or features are not intended to limit the invention.The singular forms “a”, “an”, and “the” are intended to include theplural forms as well, unless the context indicates otherwise. And, theterms “comprises”, “includes”, “has”, and the like specify the presenceof stated features, steps, operations, elements, and/or components butdo not preclude the presence or addition of one or more other like,similar, or different features, steps, operations, elements, components,and/or groups.

It should be understood that although this description is made to besufficiently clear, concise, and exact, scrupulous and exhaustivelinguistic precision is not always possible or desirable. For example,considering a video signal, a skilled reader will understand that anoscilloscope described as displaying the signal does not display thesignal itself but a representation of the signal, and that a videomonitor described as displaying the signal does not display the signalitself but video information the signal carries.

Elements described in detail with reference to one embodiment,implementation, or application optionally may be included, wheneverpractical, in other embodiments, implementations, or applications inwhich they are not specifically shown or described. For example, if anelement is described in detail with reference to one embodiment and isnot described with reference to a second embodiment, the element maynevertheless be claimed as included in the second embodiment. Thus, toavoid unnecessary repetition in the following description, one or moreelements shown and described in association with one embodiment,implementation, or application may be incorporated into otherembodiments, implementations, or aspects unless specifically describedotherwise, unless the one or more elements would make an embodiment orimplementation non-functional, or unless two or more of the elementsprovide conflicting functions.

Elements described as coupled may be electrically or mechanicallydirectly coupled, or they may be indirectly coupled via one or moreintermediate components.

Aspects of the invention are described primarily in terms of animplementation using a da Vinci® Surgical System, commercialized byIntuitive Surgical, Inc. of Sunnyvale, Calif. Examples of such surgicalsystems are the da Vinci Xi® Surgical System (Model IS4000) and the daVinci Si® Surgical System (Model IS3000). Knowledgeable persons willunderstand, however, that inventive aspects disclosed herein may beembodied and implemented in various ways, including computer-assistedand hybrid combinations of manual and computer-assisted embodiments andimplementations. Implementations on da Vinci® Surgical Systems (e.g.,the Model IS4200, the Model IS4000, the Model IS3000, the Model IS2000,the Model IS1200) are merely exemplary and are not to be considered aslimiting the scope of the inventive aspects disclosed herein. Asapplicable, inventive aspects may be embodied and implemented in bothrelatively smaller, hand-held, hand-operated devices and relativelylarger systems that have additional mechanical support.

Teleoperated surgical systems that operate at least in part withcomputer assistance (“telesurgical systems”) include bothmechanically-grounded and hand-held devices. Such telesurgical systemstypically include one or more surgical instruments for therapeutic,diagnostic, or imaging use. In hand-held telesurgical systems, such assurgical staplers and bone tools, the instrument and hand-held portionare typically combined. In mechanically-grounded systems, the instrumentis typically mechanically supported with reference to a mechanicalground.

This description concentrates on mechanically-grounded telesurgicalsystems, although aspects apply to hand-held telesurgical systems asappropriate. An example of a mechanically-grounded telesurgical systemis the da Vinci® Surgical System. Persons of skill in the art will befamiliar with various telesurgical system architectures, such as onesdescribed in U.S. Pat. No. 6,246,200 B1 (filed Aug. 3, 1999), U.S. Pat.No. 6,331,181 B1 (filed Oct. 15, 1999), and U.S. Pat. No. 6,788,018 B1(filed Dec. 20, 2001).

FIG. 1 is a schematic view of a telesurgical system 100 and a surgicalinstrument 102 associated with the telesurgical system. System 100 andinstrument 102 are illustrative of various telesurgical systemconfigurations. As shown, major components of the telesurgical systeminclude a teleoperated manipulator 104, a base unit 106, and a computercontrol system 108. These major components and their associatedfunctions may be configured as a single unit, or they may be distributedamong two, three, or more separate and interconnected units. Forexample, the da Vinci Xi® Surgical System includes a teleoperatedmanipulator system that is located next to a patient (a “patient-sideunit”), a surgeon control unit located remote from the patient-sideunit, and an auxiliary equipment unit.

Manipulator 104 includes a series of links interconnected by joints andextends from base unit 106 to a distal instrument drive interface 110,on which instrument 102 is mounted. As shown, manipulator 104 isillustrative of various teleoperated manipulator configurations thatmove instrument 102 as a whole, move one or more individual componentsof instrument 102 while keeping the main portion of instrument 102stationary, or both. Manipulator 104 operates under the control of asurgeon, who inputs motion control and instrument function operatingcommands to control system 108, which in turn commands manipulator 104to execute the corresponding movement or function. In optional aspects,however, control system 108 may autonomously command certain manipulator104 movements or instrument 102 functions associated with carrying out amedical procedure.

As shown, base unit 106 is mechanically grounded, although it mayoptionally be ungrounded, for example in hand-held embodiments. Baseunit 106 is illustrative of various separate or combined configurationsof one or more patient-side units (e.g., a single unit with two or moremanipulators, two or more units each with a single manipulator, etc.), asurgeon control unit, and one or more auxiliary equipment units.

Computer control system 108 may be centralized or distributed within thetelesurgical system. And as discussed below, aspects of computer controlsystem 108 and instrument data associated with computer control system108 may be remote from the telesurgical system, for example at alocation in a network to which the telesurgical system is coupled.Computer control systems are known, and they generally include a logicunit and a memory system that stores instructions to be carried out bythe logic unit and data acted on by the logic unit. U.S. Pat. No.6,424,885 B1 (filed Aug. 13, 1999), which is incorporated herein byreference, is an example of a computer control system for a telesurgicalsystem.

Computer control system 108 receives a user's surgical instrumentmovement commands via master input 112 and correspondingly controlsmanipulator 104 so that instrument 102 motions are slaved to masterinput 112 motions. Master input 112 may optionally have one or moreadditional control inputs that control instrument 102 functions viacontrol system 108, such as electrosurgical energy application, surgicalstaple application, etc. As shown, computer control unit 108 alsoreceives a user's instrument operating mode commands via operating modeinput 114. Aspects of these operating modes will be discussed in detail.Operating mode input 114 may be combined with master input 112 or it maybe separately located. For example, operating mode input 114 may be aswitch on the master input or on a surgeon control unit touch pad orsimilar input device.

Referring to FIG. 2, instrument 102's major components include aproximal end mechanism 116, a hollow instrument shaft 118 coupled at oneend to proximal end mechanism 116, a movable surgical end effector 120coupled to the distal end of instrument shaft 118, and an optionalmovable wrist mechanism 122 coupled between the distal end of shaft 118and end effector 120. Proximal (located away from the patient) anddistal (located toward the patient) directions are indicated in thefigure for clarity. Instrument shaft 118 may be straight or curved orjointed, and the shaft may be rigid or flexible. End effector 120carries out a therapeutic, diagnostic, or imaging surgical function, orany combination of these functions. Various instrument wrist mechanismconfigurations are known—see e.g., U.S. Pat. No. 6,394,998 B1 (filedSep. 17, 1999), U.S. Pat. No. 6,817,974 B2 (filed Jun. 28, 2002), U.S.Pat. No. 9,060,678 B2 (filed Jun. 13, 2007), and U.S. Pat. No. 9,259,275B2 (filed Nov. 12, 2010), the disclosures of which are incorporatedherein by reference.

As shown, proximal end mechanism 116 includes two illustrative rotatingcable drive capstans 124 a,124 b surrounded by a housing 126. A firstpair of cables 128 a,128 b is wrapped around capstan 124 a so that onecable pays out and the other cable pays in as capstan 124 a rotates, andvice-versa. Similarly, a second pair of cables 130 a,130 b is wrappedaround capstan 124 b so that one cable pays out and the other cable paysin as capstan 124 b rotates, and vice-versa. The capstans 124 a,124 breceive drive inputs from instrument drive interface 110 under thecontrol of control system 108, as described previously.

Cables 128 a,128 b extend through instrument shaft 118 and are coupledto a movable end effector component 132, such as a movable jaw, scissorblade, electrocautery hook or blade, and the like. Accordingly, endeffector component 132 moves in correspondence with capstan 124 arotation. Likewise, cables 130 a,130 b extend through instrument shaft118 and are coupled to wrist 122 so that wrist 132 moves incorrespondence with capstan 124 b rotation. Wrist 122 is illustrative ofvarious jointed mechanical wrist configurations, such as nested-clevisand serial link (“snake”) configurations of Endowrist® SurgicalInstruments commercialized by Intuitive Surgical.

The capstans 124 a,124 b and their associated drive inputs, cablerouting guides or pulleys, bearings, etc. are illustrative of variousmechanisms (“transmission mechanisms”) that receive a force or torquedrive input and transmit the received drive input to correspondingmotion used to control a distal instrument component, such as wrist 122or end effector component 132. Such transmission mechanisms includerotating disk and various other axially rotating inputs; rotating, rack,or worm gear inputs; lever or gimbal inputs; sliding tab and otherlaterally translating inputs; pin and other axially translating inputs;fluid pressure inputs; and the like. Further, capstans 124 a,124 b areillustrative of instrument configurations in which one or more motorsare mounted within or are coupled to housing 126 and receive motorcontrol input from control system 108 through housing 126. The motor ormotors drive a corresponding transmission mechanism. Thus an instrumentcomponent may be moved by a motor outside (e.g., in a manipulator towhich the instrument is mounted, or mounted to the instrument) or insidethe instrument.

The cable pairs 128 a,128 b and 130 a,130 b are illustrative of variouscomponents (“actuation components”) optionally used to transfer force ortorque from a transmission mechanism to a distal end component of theinstrument. Such actuation components include tension components (e.g.,cables, cable-hypotube combinations, pull rods, etc.), compressioncomponents (e.g., push rods, Bowdin cables, etc.), rotating components(e.g., shafts, gear trains, etc.), and components that combine thesecharacteristics (e.g., push/pull rods, splined shafts that rotate andtranslate, etc.).

Additional transmission mechanism and actuation components includerotating shafts, gears, hinges, pivot points, rolling surfaces, rotatingor sliding parts, cam surfaces and cam pins, lead screws, universal orconstant-velocity joints, load bearing bearings, surfaces, or points,and the like.

Operating Modes

In an inventive aspect, a parameter that affects instrument life isdivided into two or more ranges—one range having relatively less affecton instrument life, and the other range(s) having relatively more affecton instrument life. Instrument life is extended by operating theinstrument within the parameter range having relatively less affect oninstrument life, although the parameter range(s) having relatively moreaffect on instrument life are available if needed. An example parameteris a mechanical component range of motion (“ROM”). Inventive aspects aregenerally illustrated by telesurgical system components having two ROMsavailable for user selection, and it should be understood that aspectsinclude systems having three or more ROMs that are available for userselection. In addition, inventive aspects are illustrated by mechanicalROMs, but persons of skill in the art will understand that otherinstrument or telesurgical system parameter ranges may be defined andselected, as described below. Thus two, three, or more parameter rangesmay be selected.

FIG. 2 illustrates that instrument 102's movable distal end componentseach have a ROM. And, in accordance with inventive aspects, one or moredistal end component ROMs may be selectively varied. Any limited ROM orROMs within a component's maximum ROM may be defined to be selected byoperating in a corresponding operating mode. As shown, for example, endeffector component 132 rotates around axis 134 within a first selectedROM 134 a (e.g., ±30°) or within a second selected ROM 134 b (e.g.,±60°) larger than the first selected ROM. Similarly, wrist 122 rotatesaround axis 136 within a first selected ROM 136 a (e.g., ±30°) or withina second selected ROM 136 b (e.g., ±60°) larger than the first selectedROM. The various selected ROMs are optionally symmetric or asymmetric(e.g., ±30°, +0° to −45°, +45° to −15°, +30° to +60°, etc.). And, thefirst and second ROMs may fully overlap (e.g., a first ROM ±60° and asecond ROM ±30° from a reference angle) or partially overlap (e.g., afirst ROM +15° to −45° and a second ROM 0° to −60° from a referenceangle). The selected ROM will correspond to the type of joint (e.g., arotational joint has selected rotational ROMs, a prismatic joint hasselected translation ROMs, etc.).

The illustrated wrist 122 and end effector component 132 are shownhaving a single mechanical degree of freedom (“DOF”). But, if a singlejoint or joint assembly is capable of two or more DOFs that each have anassociated ROM, the DOFs and the ROMs associated with the DOFs may beselectively limited in various ways. For example, one selected ROM forsuch a joint or joint assembly may limit a first DOF ROM but not asecond DOF ROM, and a second selected ROM for such a joint or jointassembly may limit both the first DOF ROM and the second DOF ROM. Asanother example, an instrument wrist mechanism may include two or moresingle-DOF mechanical joints but is controlled as a single joint havingmultiple DOFs, and so many selectable wrist mechanism ROMs are possible(e.g., pitch ±45° and yaw ±45°; pitch ±60° and yaw ±60°; pitch +15° to−45° and yaw ±45°, etc.). In some aspects, a selected ROM corresponds toa full mechanical ROM (i.e., mechanical stop-to-stop) for a singlemechanical joint.

Further, in telesurgical systems having more than one instrument, aselected ROM may apply to a single instrument or to a group of two ormore instruments. For example, in a first telesurgical system operatingmode, a first selected ROM corresponds to two or more instrumentsoperating at their full mechanical ROMs, and a second selected ROMcorresponds to two or more instruments operating within a limited ROM.Alternately, selectable ROMs are independently available for two or moreindividual instruments.

In another aspect, two or more ROMs available for selection depend onthe specific type of instrument mounted to a manipulator. For example, afirst instrument type (e.g., a grasper) may have two selectableoperating modes: a first mode in which the first instrument wrist's fullpitch and yaw ROMs are available, and a second mode in which the firstinstrument wrist's pitch and yaw ROMs are limited (e.g., ±45°). A secondinstrument type (e.g., monopolar cautery shears) may have two differentselectable operating modes: a first mode in which the second instrumentwrist's full pitch and yaw ROMs are available, and a second mode inwhich the second instrument wrist's pitch and yaw ROMs are limited(e.g., ±30°). Likewise, a first instrument type may have one quantity(e.g., two) of selectable ROMs available, and a second instrument typemay have a different quantity (e.g., three) of selectable ROMsavailable. And in some aspects, one specific instrument type may nothave any selectable ROMs available (i.e., the full instrument ROM(s) arealways available), and another specific instrument type has two or moreselectable ROMs available.

In accordance with an inventive aspect, these operating modes are usedto extend instrument life in a telesurgical system, as described below.

Operating Parameter Ranges

Various operating parameters may be used to describe the environment inwhich control system 108 commands instrument and instrument componentmovement. One parameter is position or orientation within a range ofmotion, as discussed above. Other parameters include componentvelocities, accelerations, static force or torque applications andloads, and dynamic force or torque applications and loads. Thus variousranges within these parameters may be defined and selected as describedabove.

For example, FIGS. 3A-3C illustrate instrument operating parameters.FIG. 3A is a schematic of an instrument 151 having a snake-like distalend (e.g., a catheter, a guide tube, etc.). Double-headed arrow 150represents a full parameter range associated with movement of a flexibleinstrument component, such as mechanical ROM, lateral force, distal tipvelocity, distal tip acceleration, pull force on an actuation cable,etc. constrained by the physical limits of the instrument and associatedactuation components. Double-headed arrow 152 represents a limitedparameter range as constrained by the control system.

FIG. 3B is a schematic of an instrument component 155 translating at aprismatic joint (e.g., a push rod, a knife blade, a stapler sled, etc.).Double-headed arrow 154 represents a full parameter range associatedwith straight or curvilinear translation, such as mechanical ROM, axialpush or pull force, component velocity, component acceleration, etc.constrained by the physical limits of the joint, the component, and theassociated actuation components. Double-headed arrow 156 represents alimited parameter range as constrained by the control system.

FIG. 3C is a schematic of a cross section of an instrument component 159(e.g., a rotating drive shaft, a disk, a gear, a hinge pin, etc.).Double-headed arrow 158 represents a full parameter range associatedwith rotation, such as mechanical ROM, torque, angular velocity, angularacceleration, etc. constrained by the physical limits of the componentand the associated actuation components. Double-headed arrow 160represents a limited parameter range as constrained by the controlsystem.

During operation of the telesurgical system, the value of each of theseparameters can be determined within a range, and so the control systemmay record the amount of time a component spends within a predefinedparameter range. Likewise, the control system may record the number ofevents associated with a parameter range or value.

For example, the control system may record the amount of time a moveablecomponent operates within a parameter range, such as the amount of timea component operates within a 60-90-degree ROM. Or, events such as thenumber of times the component moves into the 60-90-degree ROM or thenumber of times the component exceeds 60 degrees may be recorded.

In accordance with an inventive aspect, information about theseparameter ranges or events is used to extend instrument life in atelesurgical system, as described below. This information may becombined with information about the selected parameter operating range.Or, it may be used independently of any selected operating parameterrange.

Instrument Life

As with all mechanisms, movable instrument components can degrade fromuse. Therefore, for safety a telesurgical system typically limits thetime an instrument may be used. For example, an instrument design istested to determine expected average maximum life, and then a largesafety margin is introduced to define a maximum usable life that isshorter than the expected average maximum life.

The maximum usable life may be defined in various ways, such as bydefining maximum instrument allowable discrete uses (“lives”) or bydefining a maximum instrument allowable time in use. For example, a newindividual instrument may be assigned an allowed ten usable discretelives, and the number of usable discrete lives remaining is stored inmemory in the instrument, in the telesurgical system, or at a networkedlocation, so control system 108 can access the stored information.Likewise, a new individual instrument may be assigned an allowed usabletime, and the time of allowable use remaining is stored in memory in theinstrument, in the telesurgical system, or at a networked location, socontrol system 108 can access the stored information. Once the maximuminstrument allowable discrete uses or the maximum instrument allowableusable time is assigned, the number of discrete uses remaining or theusable time remaining is reduced as the instrument is used duringmedical treatment.

In one example variation, one usable discrete life is decremented foreach surgical procedure (single patient—start to finish) in which theinstrument is used until zero usable discrete lives remain, at whichtime the surgical system prevents further use of the individualinstrument.

In another example variation, one usable discrete life is decrementedeach time the individual instrument is mounted and initialized on amanipulator until zero usable discrete lives remain.

In another example variation, as the instrument is used, the surgicalsystem decrements usable time remaining until zero usable time remainingexists. When zero usable time remains, the surgical system optionally(a) prevents further use of the instrument and signals that areplacement instrument is required; (b) allows use of the instrument tobe continued until the instrument is removed from the manipulator andprevents further use of the instrument after the instrument is removedfrom the manipulator; or (c) allows use of the instrument to becontinued during an entire surgical procedure, including one or moreremovals and one or more later mountings to a manipulator, and thenprevents further use of the instrument after the surgical procedure.

Thus the usable life of an instrument begins at a defined initialmaximum usable life, and the usable life of the instrument is reduced asthe instrument is used until zero usable life remains for theinstrument. Usable life of an instrument is illustrated in thisdescription by discrete lives remaining or time of use remaining, butother measures of usable life may be applied, such as instrumentperformance measurement (e.g., sensed actual component position inrelation to commanded component position, sensed electrosurgical energy,sensed torque for surgical staple formation, etc.) as a dynamicindication of usable life remaining.

The usable life of an individual instrument, such as allowable discretelives or time of use remaining, may optionally be stored in theinstrument itself, in the telesurgical system, or at a network locationwith which the telesurgical system communicates. And, updates to theusable life may optionally be made at various times. For example, timeremaining may be continuously updated while the instrument is in use, orthe control system may record the total time the instrument is used andupdate the usable time remaining when the instrument is withdrawn fromthe patient. Similarly, the usable discrete lives remaining may bedecremented while the instrument is in use, or the control system maydetermine the discrete lives used and update the discrete livesremaining when the instrument is withdrawn. As another example, the timeor discrete lives used may be recorded for an instrument for the timethe instrument is mounted to a manipulator, and then the time or livesremaining is updated when the instrument is again coupled to amanipulator.

Referring again to FIG. 2, in one aspect surgical instrument 102includes a memory 138, which in some embodiments includes storedinformation such as instrument type, a serial number unique to theinstrument, usable life remaining (e.g., number of allowable discretelives or allowable time remaining), etc. This information stored inmemory 138 is communicated 140 via drive interface 110 to control system108. Optionally, information such as updated allowable discrete lives ortime remaining is communicated 140 from control system 108 via driveinterface 110 to memory 138 so that the information can be accessed thenext time the instrument is used in the teleoperated surgical system. Anexample of instrument memory and communication via a drive interface isfound in U.S. Pat. No. 6,331,181 B1 (filed Oct. 15, 1999), which isincorporated herein by reference. Likewise, the instrument discrete lifeor time information may be stored at a network location accessed bycontrol system 108 of the telesurgical system.

The amount of degradation of an instrument's capability in manysituations varies depending on the operating parameter range in whichthe instrument is used. For example, as an instrument component moveswithin its associated DOF ROM, more mechanical degradation may beexpected in the component at the extremes of the ROM than near thecenter of the ROM. More specifically, a cable used to move an endeffector jaw may experience relatively less degradation over time as thecable is routed around one or more pulleys or guide surfaces to move thejaw ±30 degrees from a defined center position (e.g., the instrument'slongitudinal axis between proximal and distal ends), and the cable mayexperience relatively more degradation over time as the cable is routedaround the one or more pulleys or guide surfaces to move the jaw ±60degrees from the defined center position, and the cable may experiencerelatively even more degradation over time as the cable is routed aroundthe one or more pulleys or guide surfaces to move the jaw ±90 degreesfrom the defined center position.

Further, the amount of degradation may not be a linear function of theparameter value within a range of parameter values. For example,transmission mechanism component or actuation component degradation maynot be a linear function of the associated distal end component's ROMlocation. As a more specific example, component degradation for endeffector jaw movement near the jaw's maximum ROM (e.g., near 90 degrees)may be significantly higher (e.g., more than 3×) than for jaw movementnear the defined center position or within a limited ROM (e.g., ±30degrees), although 90 is three times 30.

In addition, a movable component may degrade relatively more quickly asits velocity or acceleration increases. For example, a component mayexperience relatively higher degradation over time if its velocity islimited only by the component's maximum possible actuated velocity, andit may experience relatively lower degradation over time if its velocityis limited to a value less than the component's maximum possibleactuated velocity. Similarly, a component may experience relativelyhigher degradation over time if its acceleration is limited only by thecomponent's maximum possible actuated acceleration, and it mayexperience relatively lower degradation over time if its acceleration islimited to a value less than the component's maximum possibleacceleration.

Further, a movable transmission mechanism component or actuationcomponent may degrade relatively more quickly as a static force ortorque load, dynamic mechanical actuation force or torque load, or acombined static load and dynamic actuation load on the part increases.For example, a component may experience relatively higher degradationover time if its maximum permitted actuation load is the maximumpossible actuation load (e.g., to cause maximum grip force, maximumbending force, or maximum torque on a component; working near or in acomponent's range of elastic deformation) and relatively lowerdegradation over time if its maximum permitted actuation load is lessthan the maximum possible actuation load. Load may be directly measured(e.g., by using a force or torque sensor coupled to the component) orindirectly measured (e.g., by sensing motor current in the motor used tomove the component or to hold it in place under load, and then inferringload from the motor current used).

Similarly, in an instrument in which a constantly present preload forceor torque is on a component (e.g., a cable), the component mayexperience relatively higher degradation over time if its preload forceor torque is at a first value as actuation force or torque is applied,and may experience relatively lower degradation over time if its preloadforce or torque is at a second value, less than the first value, asactuation force or torque is applied. An example of such preload forceis a constant preload tension force on actuation cables in an instrumentin order to keep the cables from going slack or leaving their definedpaths. Another example of a preload force is the force experienced in atransmission mechanism or actuation component that is used to eliminatelost motion caused by gaps (backlash) in an antagonistic control pair inwhich one of the pair moves an instrument component in one direction(e.g., pitch/heave up, yaw/sway left, roll clockwise, surge proximally)and the other drivetrain of the pair moves the instrument component inthe opposite direction (e.g., pitch/heave down, yaw/sway right, rollcounterclockwise, surge distally). Thus a component may experiencerelatively higher degradation over time with a combination of relativelyhigher preload force and an actuation force, and a relatively lowerdegradation over time with a combination of a relatively lower preloadforce and the same actuation force. In addition, a long-term static loadalone may result in mechanical degradation, such as cable stretch underhigh preload tension for many months. The amount of time between when aninstrument was built (e.g., when the static preload force is firstapplied) and the time the instrument is used may be relevant toinstrument performance.

Determining Instrument Life

In one aspect the control system records the amount of time spent ineach of two or more operating modes in which a parameter is differentlylimited, and then these times are used to determine usable instrumentlife remaining. For example, the control system records the time spentin a first selected mode in which a ROM is limited and the time spent ina second selected mode in which the ROM is unlimited.

In another aspect the control system records the amount of time spent intwo or more parameter ranges, and then these times are used to determineusable instrument life remaining. For example, the control systemrecords the time spent within a first predefined mechanical ROM (e.g.,0-30 degrees) and the time spent in a second predefined mechanical ROMbeyond the first predefined mechanical ROM (e.g., 30-60 degrees).

In another aspect, the time spent in each of two or more operating modesand time spent in one or more parameter ranges are combined to determineusable instrument time remaining. For example, the control systemrecords the time spent in a first selected mode in which a ROM islimited (e.g., 0-45 degrees) and the time spent in a second selectedmode in which the ROM is unlimited (e.g., 0-90 degrees), and it alsorecords the amount of time spent in a predefined ROM (e.g., 70-90degrees). The control system may then use this combined information todetermine the instrument's usable life remaining.

Again, although mechanical ROMs are used as example parameters, they arerepresentative of any parameter that affects mechanical degradation overtime and that can be monitored or changed from one value to a secondvalue, or from one range of values to another range of values, and thatcorrespondingly changes the mechanical degradation over time. Inaddition, although the examples above are individual parameters such asROM, velocity, acceleration, actuation force or torque, and preloadforce or torque, two or more of these parameters may be limited tofurther reduce instrument component degradation over time. Thus the term“selected parameter range” includes a range of a single parameter andranges of two or more parameters.

As mentioned above, in some instances the degradation of an individualcomponent depends on two or more parameter values. For example, if aCarden joint is at a zero bend angle, then the Carden joint'sdegradation over time may be mainly caused by its maximum permittedvelocity or actuation load. But if the Carden joint is at a high bendangle (e.g., 60 degrees), then in a combination of this bend angle withmaximum permitted angular velocity or actuation load, or in acombination of this bend angle with maximum permitted angular velocityand actuation load, the bend angle may become the dominant parameter inthe joint's degradation over time. Thus a parameter associated withinstrument component degradation over time may have a single dimensionor may have two, three, or more dimensions. And, the value of oneparameter or one dimension of a parameter may determine a secondparameter's or a second dimension's effect on degradation over time of acomponent.

Often, one or more instrument components degrade over time sooner thanothers, and so these one or more instrument components determine theexpected average maximum life of an instrument type and consequently thedefined maximum usable life for the instrument type. Limitingdegradation over time of these one or more components increases theexpected average maximum life of the instrument type and the associateddefined maximum usable life of the instrument type.

Therefore in one aspect, maximum usable instrument life is extended in amode that limits range of one or more instrument operating parameters(such as range of motion) for one or more movable instrument components,as compared to maximum usable instrument life in a mode that does notlimit the range of the instrument operating parameter. The telesurgicalsystem's computer control unit determines the extended allowablediscrete lives or time as a function of the limited operating parameter(e.g., the time spent in the limited parameter operating mode), adjuststhe instrument's remaining allowable lives or time, and stores theadjusted allowable remaining discrete lives or time for access in one ormore subsequent surgical procedures.

The allowable discrete lives remaining may optionally be decremented infractions of discrete lives, so that operating in a mode that limits aninstrument operating parameter for two or more procedures is required toextend allowable discrete instrument lives remaining by a full discretelife.

For example, as a result of a first surgical procedure in which alimited parameter range is selected, the allowable discrete instrumentlives remaining is decremented by one-half. And, as a result of a secondsurgical procedure in which the limited parameter range is selected, theallowable discrete instrument lives remaining is decremented by anotherone-half. Therefore, after the first and second surgical procedures, theallowable discrete instrument lives remaining is extended by a fulldiscrete instrument life, because instead of two discrete livesdecremented (one per each procedure), only a single discrete life isdecremented after the two procedures. The telesurgical system determinesthe number of full discrete instrument lives remaining and so allows theadditional full discrete instrument life to be used for a subsequentsurgical procedure.

Time spent in an operating mode may optionally be correlated toextending allowable remaining discrete instrument lives or time. Forexample, during a first surgical procedure a limited operating parameterrange is selected for one half the time the instrument is used, and sothe allowable discrete instrument lives remaining is decremented bythree-quarters. Then, during a second surgical procedure the limitedoperating parameter range is selected for the full procedure, and so theallowable discrete instrument lives remaining is decremented byone-half. And, during a third surgical procedure the limited operatingparameter range is selected for three-quarters of the procedure, and sothe allowable discrete instrument lives remaining is decremented byfive-eighths. Therefore, after these three procedures the total discretelives have been decremented by less than two, and so an additionaldiscrete instrument life is available. As another example, during afirst surgical procedure a limited operating parameter range is selectedfor one-half the time the instrument is used, and so usable timeremaining is decremented by three-quarters of the full time theinstrument is used. The correlations in these examples are arbitrarilyselected as illustrations. In practice, the correlations are worked outbased on actual instrument lifecycle testing, which may vary frominstrument type to instrument type, and may vary based on parameterranges chosen.

In another aspect, maximum usable instrument life is extended by thecontrol system sensing and recording occurrences or time spent in whichone or more movable instrument components operate in one or moreoperating parameters (such as range of motion), adjusting theinstrument's remaining allowable discrete lives or time, and storing theadjusted remaining lives or time for access in one or more subsequentsurgical procedures. The adjusting may be done in a way similar to theway the adjusting is done when operating modes are discretely selected.

In another aspect, parameter ranges may be associated with usableinstrument life remaining. The instrument optionally defaults to a fullparameter range during an early portion of instrument life remaining,and then defaults to a limited parameter range during a later portion ofinstrument life remaining, with the full parameter range or an increasedparameter range available when needed. For example, for an instrumentwith a mechanical DOF having a ±90° ROM, a ±60° ROM may be available asa default when the instrument is first used, and the surgeon may selectthe full ±90° ROM when needed. As usable instrument life is consumedpast a certain value, however, the default ROM changes to ±45° ROM, andthe surgeon may select the full ±90° ROM when needed. As a furtherexample, as usable instrument life is consumed past a certain value, thedefault ROM changes to ±45° ROM, and ±60° and ±90° ROMs are madeavailable for selection when needed. As another example, as usableinstrument life is consumed past a certain value, the default ROMchanges to ±45° ROM, and the surgeon may select a less limed ±60° ROMwhen needed, but the full ±90° ROM is not available for selection. Inthis situation, if the full parameter range is needed, an instrumenthaving the unconstrained full parameter range must be used.

In a variation of this aspect, parameter ranges are associated withusable instrument life remaining without having two or more selectableparameter ranges. As usable instrument life is consumed, the parameterrange is correspondingly limited. For example, during an early portionof usable instrument life, a full parameter range is available, andduring a later portion of usable instrument life, only a limitedparameter range is available. Again, if the full parameter range isneeded, an instrument having the unconstrained full parameter range mustbe used.

Selecting an Operating Mode

Referring once again to FIG. 1, in one aspect a surgeon selects one oftwo or more instrument operating parameter limits as described above byentering a selection via operating mode input 114 on a surgeon controlunit. Generally, in one operating mode the full parameter range isavailable to the surgeon if clinically required. The parameter range islimited in the second operating mode. The telesurgical system mayoptionally operate in various other operating modes (third, fourth,fifth, etc.) that either further limit one parameter's range, limit oneor more additional parameter ranges, or both.

In one aspect, a teleoperated surgical system defaults to a firstoperating mode in which an instrument operating parameter range islimited to a first range, and the surgeon may select a second operatingmode in which the instrument operating parameter range is limited to asecond range that is either larger than the first range or not limited.For example, the teleoperated surgical system is initialized in a firstoperating mode in which instrument wrist pitch and yaw ROMs are limitedto ±45°, and the surgeon may then select a second operating mode inwhich the instrument pitch and yaw ROMs are unlimited or limited to ator near the full possible physical ROMs. A limited range default mayoccur upon system start-up, upon instrument installation, uponreestablishing the master-slave relationship after an interruption, uponsensing operation within the limited range for a predetermined time, orupon any other relevant system event.

In one aspect, a teleoperated surgical system defaults to a firstoperating mode in which an instrument operating parameter range is notlimited or is limited to near the parameter's full range, and thesurgeon may select a second operating mode in which the instrumentoperating parameter range is limited. For example, the teleoperatedsurgical system is initialized with instrument wrist pitch and yaw ROMsare unlimited or limited to at or near the full possible physical ROMs,and the surgeon may then select a second operating mode in which theinstrument pitch and yaw ROMs are limited to ±45°. An unlimited rangedefault may occur upon system start-up, upon instrument installation,upon establishing the master-slave relationship after an interruption,upon sensing a predetermined number of times within a predetermined timeperiod that a master haptic limit for the parameter is reached, or uponany other relevant system event.

In one aspect, when a telesurgical system is operating in a mode inwhich an instrument operating parameter is limited, the telesurgicalsystem's computer control system limits a corresponding master inputparameter to help the surgeon understand that the parameter is limited.For example, in a telesurgical system operating mode in which a movableinstrument component ROM is limited, the corresponding master ROM islimited. If a first operating mode limits the instrument ROM componentto ±45°, the control system places a haptic limit on the master thatlimits the corresponding master DOF to ±45°. This allows the surgeon tosense the limited ROM, and then to select the second operating mode inwhich the ROM is unlimited if additional instrument component ROM isdesired. As described above, the surgeon may select the second operatingmode in various ways, such as by a discrete selection on the master oron the surgeon control unit, by moving through a haptic sensory cue(e.g., a haptic “wall”), or by any other suitable control input (e.g.,foot pedal, voice, eye gaze menu selection, etc.).

In one aspect, the control system automatically selects an operatingmode associated with a limited parameter range after a movablemechanical component has operated within the limited parameter range fora predetermined amount of time. For example, the control system mayinitially select a first, limited parameter range (e.g., ±60° ROM)operating mode when an instrument is first installed. Then, a surgeonselects and uses a second, unlimited parameter range (e.g., ±90° ROM)operating mode because of a clinical requirement. As the surgeoncontinues to work for a defined time, the control system determines thatthe surgeon is no longer using the unlimited parameter range, and so thecontrol system once again selects the first, limited parameter range toprevent the surgeon from inadvertently operating in the second parameterrange that results in increased component mechanical degradation. Thesurgeon may once again select the second operating mode if necessary.

1. A telesurgical system comprising: a teleoperated manipulator; and acontrol system; wherein the control system operates the telesurgicalsystem in a first operating mode in which the control system drives amechanical component of a surgical instrument coupled to the manipulatorwithin a first range of an operating parameter; and wherein the controlsystem operates the telesurgical system in a second operating mode inwhich the control system drives the mechanical component of the surgicalinstrument coupled to the manipulator within a second range of theoperating parameter less than the first range of the operatingparameter.
 2. The telesurgical system of claim 1: wherein the firstrange of the operating parameter comprises a first range of motion of amechanical degree of freedom; and wherein the second range of theoperating parameter comprises a second range of motion of the mechanicaldegree of freedom.
 3. The telesurgical system of claim 1: wherein thefirst range of the operating parameter comprises a first range of motionof a first mechanical degree of freedom and a first range of motion of asecond mechanical degree of freedom; and wherein the second range of theoperating parameter comprises a second range of motion of the firstmechanical degree of freedom and a second range of motion of the secondmechanical degree of freedom.
 4. The telesurgical system of claim 1:wherein the first range of the operating parameter comprises a firstrange of velocities of a component of the surgical instrument; andwherein the second range of the operating parameter comprises a secondrange of velocities of the component of the surgical instrument.
 5. Thetelesurgical system of claim 1: wherein the first range of the operatingparameter comprises a first range of accelerations of the component ofthe surgical instrument; and wherein the second range of the operatingparameter comprises a second range of accelerations of the component ofthe surgical instrument.
 6. The telesurgical system of claim 1: whereinthe first range of the operating parameter comprises a first range of amechanical load on the component of the surgical instrument; and whereinthe second range of the operating parameter comprises a second range ofmechanical load on the component of the surgical instrument.
 7. Thetelesurgical system of claim 1: wherein on the condition that thecontrol system operates the telesurgical system solely in the firstoperating mode during a surgical procedure, the control systemdecrements remaining usable life of the surgical instrument by a firstamount; and wherein on the condition that the control system operatesthe telesurgical system in the second operating mode during the surgicalprocedure, the control system decrements the remaining usable life ofthe surgical instrument by a second amount less than the first amount.8. The telesurgical system of claim 1: wherein the control systemdecrements usable time remaining for the surgical instrument by a firstamount as a result of the telesurgical system operating in the firstoperating mode; and wherein the control system decrements the usabletime remaining for the surgical instrument by a second amount less thanthe first amount as a result of the telesurgical system operating in thesecond operating mode.
 9. The telesurgical system of claim 1: whereinthe control system decrements a number of discrete lives remaining forthe surgical instrument by a first amount as a result of thetelesurgical system operating in the first operating mode; and whereinthe control system decrements the number of discrete lives remaining forthe surgical instrument by a second amount less than the first amount asa result of the telesurgical system operating in the second operatingmode.
 10. The telesurgical system of claim 1: wherein the control systemdecrements a number of discrete lives remaining for the surgicalinstrument by one discrete life as a result of the telesurgical systemoperating in the first operating mode during an entire surgicalprocedure; and wherein the control system decrements the number ofdiscrete lives remaining for the surgical instrument by less than onediscrete life as a result of the telesurgical system operating in thesecond operating mode during the entire surgical procedure.
 11. Thetelesurgical system of claim 1: wherein the control system decrements anumber of discrete lives remaining for the surgical instrument by onediscrete life as a result of the telesurgical system operating in thefirst operating mode for a predetermined amount of time; and wherein thecontrol system decrements the allowable number of discrete livesremaining for the surgical instrument by less than one discrete life asa result of the telesurgical system operating in the second operatingmode for the predetermined amount of time.
 12. The telesurgical systemof claim 1, further comprising: an operating mode input; wherein thecontrol system changes from operating the telesurgical system in thesecond operating mode to operating the telesurgical system in the firstoperating mode in response to a user input received at the operatingmode input.
 13. The telesurgical system of claim 12: wherein after thecontrol system changes from operating the telesurgical system in thesecond operating mode to operating the telesurgical system in the firstoperating mode in response to the user input, the control system changesfrom operating the telesurgical system in the first operating mode tooperating the telesurgical system in the second operating mode inresponse to a determination that the control system has driven themechanical component of the surgical instrument solely within the secondrange of the operating parameter for a predetermined amount of time. 14.A telesurgical system comprising: a surgical instrument comprising amovable component; and a control system; wherein the control systemoperates the component of the surgical instrument within a first rangeof an operating parameter for a first amount of time; wherein thecontrol system operates the component of the surgical instrument withina second range, smaller than the first range, of the operating parameterfor a second amount of time; wherein the control system decrements ausable time remaining for the surgical instrument by a first amountbased on the first amount of time; and wherein the control systemdecrements the usable time remaining for the surgical instrument by asecond amount, less than the first amount, based on the first amount oftime.
 15. A telesurgical system comprising: a surgical instrumentcomprising a movable component; and a control system; wherein thecontrol system operates the component of the surgical instrument withina first range of an operating parameter for a first amount of time;wherein the control system operates the component of the surgicalinstrument within a second range, smaller than the first range, of theoperating parameter for a second amount of time; wherein the controlsystem decrements a number of discrete lives remaining for the surgicalinstrument by a first amount based on the first amount of time; andwherein the control system decrements the number of discrete livesremaining for the surgical instrument by a second amount less than thefirst amount based on the second amount of time.
 16. The telesurgicalsystem of claim 15: wherein the first amount of the number of discretelives remaining for the surgical instrument is less than a full discretelife.
 17. The telesurgical system of claim 15: wherein the second amountof the number of discrete lives remaining for the surgical instrument isless than a full discrete life.
 18. The telesurgical system of claim 15:wherein the first range of the operating parameter comprises a firstrange of velocities of the component; and wherein the second range ofthe operating parameter comprises a second range of velocities of thecomponent.
 19. The telesurgical system of claim 15: wherein the firstrange of the operating parameter comprises a first range ofaccelerations of the component; and wherein the second range of theoperating parameter comprises a second range of accelerations of thecomponent.
 20. The telesurgical system of claim 15: wherein the firstrange of the operating parameter comprises a first range of a mechanicalload on the component; and wherein the second range of the operatingparameter comprises a second range of mechanical load on the component.